President Barack Obama is getting an up-close view Thursday of the world's largest sanctuary for ocean life, a week after he signed off on a massive expansion of the protected area extending northwest from the islands of Hawaii.

Ahead of his visit to the Papahanaumokuakea Marine National Monument, Obama told a gathering of Pacific island nation leaders that conservation has been a key part of his presidency.

"This is a hallowed site and it deserves to be treated that way and from now on it will be preserved for our future generations."

The White House says the protected area encompassing 362,000 square kilometers is home to more than 7,000 marine species, one-quarter of which are not found anywhere else.

Obama also spoke Wednesday night about the importance of addressing climate change, saying no nation is immune from the threat and that the world will have to tackle it together.